As one example of a method for searching for encoded data of a sound signal or moving image data, a method for searching for encoded data according to search conditions including a pitch (a fundamental frequency) of sound has been proposed. The encoded data of a sound signal is obtained by performing entropy encoding on a residual signal calculated by performing linear prediction analysis on the sound signal. In this type of search method, encoded data is decoded into a sound signal, the pitch of the sound signal is calculated, and it is determined whether the pitch satisfies search conditions (see, for example, Patent Document 1 and Non-Patent Document 1).
Patent Document 1: Japanese Laid-open Patent Publication No. 2010-160439
Non-patent Document 1: SADAOKI FURUI, Digital Speech Processing (Digital Technology Series; 6), Tokai University Press, Sep. 25, 1985, pp. 57-59 and 69-73